Kawasaki KX80 Specs and Review: Off-Road Dirt Bike

Kawasaki’s KX80 may not be the first name on the minibike map, but its performance is second to none. And this should be no surprise, especially from a pit bike belonging to the famed KX™ lineup. Despite the segment being dominated by Suzukis and Hondas, the KX80 still made a breakthrough and even introduced the concept of MX racing to hobbyists and beginners.

The Kawasaki KX80 is an 82-cc Enduro-style dirt bike produced by Kawasaki from 1979 to 2000. Unpretentious and inclusive, this small, powerful two-wheeler boasted a 13-inch ground clearance, 75-mph top speed, and stark but rugged styling that seemed to call for serious mudding and wooded trails.

In the past, riders deemed the timing of its launch inopportune – but they do not seem to think so now. The KX80’s may have been a few years late. But its overall design and functionality have stood the test of time and changing trends. Recently, It has become the go-to vehicle for youngsters wanting to start early in off-roading and mechanics looking for their next project build.

Quite an amazing bike, right? Read on and get to know more about this classic two-wheeler.

Dirt Bike Riding on Rocks

The KX80: Kawasaki’s Super Minibike

The Kawasaki KX80 is an MX-oriented dirt bike produced from 1979 to 2000 and Team Green’s response to the emerging superclass minibikes of the early ’80s. Despite being characteristically detuned compared to adult-size motocrossers, this beginner-rate wheeler is still formidable in its own right.

It has considerable ground clearance, incredible power, and a 75-mph (121 km/h) top-speed rating that bests even 125-cc bikes. The KX80’s attributes more than compensate for its late entry into the segment. To say that it is not for the faint of heart would be quite an understatement.

It may not have been as severely criticized as the 1983 Quacker, but it is not exactly enthusiast fodder either. For onlookers whose only knowledge of the Lime Green classic is random feedback in forums and online product reviews, the bike is given very little credit for what it can do.

But for those who had the opportunity to ride the KX 80 as kids, the story is quite different. The bike is genuinely appreciated and forever an invaluable part of their childhood.

Better Late Than Never

The KX80 managed to thrive in a world dominated by Yamaha YZ and Suzuki RM minibikes – despite its untimely arrival in the scene. It was able to do so through overcompensation and a slew of innovations worthy of amateur national titles.

Kawasaki was among the first to introduce Big Wheeled versions and equip its minibike with front and rear disc brakes. Contrary to its perennial Lime Green finish, Kawasaki made sure the KX80 was ever-evolving as an in-training dirt bike and recreational ride.

Kawasaki KX80 Specs & Features

Engine

A liquid-cooled, 2-stroke single-cylinder piston reed valve engine breathes life into the Kawasaki KX80 Mini 80. It has a bore-stroke ratio of 48 × 45.8 mm (1.89 × 1.80 inches). Engine displacement is 82 cm³ (5.0 in³), while the compression ratio is 9.4:1. A 28-mm Keihin carburetor handles the air-fuel mixture. 1990 Kawasaki KX80 models used a Keihin PE26 carb with slightly different jetting (#122 main, #55 slow).

Post-1993 models have a slightly different engine configuration. Piston displacement is 79 cm³ (4.82 in³), the compression ratio is 9.1:1, and the bore-stroke ratio is 47 × 45.8 mm (1.85 × 1.80 inches). Further variances in horsepower, torque, and engine specs are in the service manual for KX80s produced between 1989 and 1997.

Either way, the above configuration lends to a KX80 top speed of 55 – 65 mph/88.5 – 105 km/h (75 mph/121 km/h, downhill on pavement), 14.2 – 15.7 Nm (1.45 – 1.6 kgf-m, 10.5 – 11.6 ft-lb) @ 11,000 – 11,500 RPM maximum torque, and 24 – 26 PS (17.7 – 19.1 kW) @ 12,000 RPM horsepower. Later-year versions had a slightly larger bore size but retained the same engine specs and torque/power outputs, performing just a tad behind the 100-cc KX introduced in 1989.

Fuel & Lubrication

Depending on the production year, the KX 80’s fuel tank capacity is anywhere between 4.5 and 5.7 L (1.2 – 1.5 US gal) of unleaded gasoline with a minimum rating of PON 90/RON 95. Compatible variants must contain < 5% MTBE (Methyl Tertiary Butyl Ether), < 10% ethanol, or < 5% methanol. Switching fuel brands is permitted, provided these conditions are met. However, refrain from mixing them to avoid knocking or pinging, which leads to potentially severe engine damage.

Lubrication-wise, it requires a petrol mix ratio of 32:1 and 0.74 US quart of SAE 10W-30 or 10W-40 K-Tech 2-stroke oil or its equivalent. The motor oil used should meet a minimum API grade of SJ meeting JASO T903 MA, MA1, MA2 standards. You can use other viscosity grades following ambient temperature.

Drivetrain

A manual (left-foot operated) 6-speed constant mesh return system, and wet, multi-disc clutch assembly deliver power to the ground. However, the bike had one less gear until after 1980. A D.I.D. 420M O-ring chain (with 120 or 126 links + joint) handles wheel spin. Like its larger-displacement siblings, the KX80’s wide-ratio transmission is responsible for its massive power output and acceleration prowess.

Although transmission gear ratios were untouched, the shaft assembly was rearranged for certain trims and model years from 1989 to 1997. Stock front and rear sprockets were initially 13/48T but later changed to 13/53T. Moreover, the rear sprocket for standard KX80s was changed to 49T, and 54T for the Big Wheel trims between 1989 and 1990.

For reference, the factory transmission gear ratios are below:

Primary Reduction Ratio3.400 (68/20)
Final Reduction Ratio3.692 (48/13) or 4.076 (53/13)
Transmission Gear Ratio (1st)2.538 (33/13)
Transmission Gear Ratio (2nd)1.875 (30/16)
Transmission Gear Ratio (3rd)1.500 (27/18)
Transmission Gear Ratio (4th)1.250 (25/20)
Transmission Gear Ratio (5th)1.090 (24/22)
Transmission Gear Ratio (6th)1.956 (22/23)
Overall Drive Ratio12.008 or 13.258 @ Top gear

Ignition

The 82-cc KX80 awakens via an electronic CDI (Capacitor Discharge Ignition) and a primary kick-start mechanism. Likewise, it uses a solid-post NGK R6252K-105 spark plug with a 0.7 – 0.8 mm/0.028 – 0.032-inch gap (or a hotter NGK BREG/BR9EG spark plug with a 0.5 – 0.6 mm/0.020 – 0.024-inch gap). Ignition timing is 9 – 12° BTDC @ 12,000 RPM (initial “F” mark).

A flywheel magneto serves as the dirt bike’s overall charging system while powering electronic accessories alongside a 6V (6.63 Ah)/10 HR YTZ7S battery (view on Amazon). Installing headlights on the KX80 requires a 12V (4 Ah)/10 HR 130-CCA YTX5L-BS battery format with assembled dimensions of 114 x 71 x 106 mm (4.50 x 2.81 x 4.19 inches – L x W x H) – the same battery used on the 2003 KFX 80.

Tires & Brake

Aluminum alloy wheels are equipped with tube-type Dunlop® K490 or K990 (EU releases) tires at the front and Dunlop® K595 or K990 tires at the back. Rim sizes differ, depending on trim and year. For instance, KX80-P and Kawasaki KX80 Big Wheel trims have 70/100 – 17 40M front and 90/100 – 14 49M rear tires. Meanwhile, bikes sold in Europe have wheels two (2) inches larger than those marketed in North America.

Cold-tire pressure can be adjusted according to terrain and riding conditions – slick or sticky surfaces would warrant a tire pressure of 80 kPa (0.8 kgf/cm², 11 psi). Similarly, hardpack, bumpy terrain requires 100 kPa (1.0 kgf/cm², 14 psi). When replacing stock rubber, it is wise to choose puncture-resistant tires like Kenda K760 Motorcycle Tires (view on Amazon). These sturdy tires will pair nicely with the bike’s 170-/202-mm front disc and 150-mm rear disc, which provide it stopping power.

Biking on Dirt and Mud

Suspension

Enclosed in the KX80’s tubular, semi-double-cradle steel frame (28° caster angle, 95 mm/3.7 inches trail, 45° steering angle) are front telescopic (air) Kayaba forks and a rear Uni-Trak® swingarm. The rear linkage mates to compression-and-rebound-damping adjustable aluminum Showa shocks.

Respectively, the suspension components provide 275 mm/10.8 inches of wheel travel (265 mm/10.4 inches for KX80-P trims). And with a 49.2-inch wheelbase and 13.2-inch ground clearance, they make smooth handling and ease of maneuverability possible.

Dimensions

Overall dimensions for KX80-N are 1,810 x 745 x 1,050 mm (71.25 x 29.3 x 41.3 inches – L x W x H). On the other hand, KX80-P measurements are somewhat longer and taller than older trims at 1,905 x 745 x 1,080 mm (75 x 29.3 x 42.5 inches – L x W x H). The saddle sits at 840 – 870 mm (33.1– 34.25 inches). Dry weight is 61 – 64 Kg (134 – 141 lbs.), while curb mass is 65 – 68 Kg (143 – 150 lbs.).

Exterior

Earlier versions of the KX 80 had box-like saddle seats in black. These were changed to blue seats in 1984, then contoured for a better fit two years after. Similarly, Kawasaki retained the sticker with blue and white stripes on the side of the tank until 1984. It also had more basics like a side stand and chain guard – unlike Honda’s CR80.

The rear side panel and front number plate were circular only during the first four years of the two-wheeler. And although decals changed every few years or so, their design became more radical for post-1990 models. The only thing kept evergreen was the KX80’s Lime Green body color – this near-stark quality is plenty enough for advanced mechanics and enthusiasts to pimp the bike.

If selected well, aftermarket parts such as ProTaper or Renthal handlebars (view on Amazon), chain and fork guards, and hand grips will add to the sportiness of the KX80. Custom-built YSS shock absorbers (view on Amazon), 428 drive chain, and corresponding sprockets go well with 100-cc-converted wheelers. In like manner, giving the KX80 appropriate lighting will aid in its street-legal conversion.

Kawasaki KX80 Price

MSRP for the Kawasaki KX 80 produced between 1979 and 2000 ranged from $699 to $3,049. The annual base price increase was quite reasonable and did not exceed $250 at a time. As for resale values, Nada Guides data and auction listings indicate a range between $200 and $2,555 – with the ’81 and ’82 models having the heftiest price tag. The Kawasaki KX 80 Big Wheel series produced from 1989 to 1994 has high retail averaging $975 – $1,550.

Year – Trim – Model NumberList PriceRetail/Trade-In Values
1979 KX80-A1 Mini 80$699$355 – $1,975
1980 KX80-A2$729$355 – $1,975
1981 KX80-C1 Mini 80$769$530 – $2,555
1982 KX80C2$749$530 – $2,555
1983 KX80E1$959$470 – $2,195
1984 KX80E2$999$405 – $1,975
1985 KX80E3$1,079$405 – $2,075
1986 KX80G1$1,199$200 – $825
1987 KX80G2$1,199$200 – $925
1988 KX80L1/M1/N1/P1$1,599$200 – $925
1989 KX80L2/M2/P2$1,799$200 – $975
1989 KX80N2 Big Wheel$1,899$200 – $975
1990 KX80L3/M3/P3$1,899$225 – $1,045
1990 KX80N3 Big Wheel$1,999$225 – $1,075
1991 KX80R1$1,999$225 – $1,110
1991 KX80T1 Big Wheel$2,099$225 – $1,110
1992 KX80R2$2,099$225 – $1,185
1992 KX80T2 Big Wheel$2,249$225 – $1,220
1993 KX80R3$2,249$225 – $1,255
1993 KX80T3 Big Wheel$2,399$250 – $1,325
1994 KX80R4$2,449$250 – $1,550
1994 KX80T4 Big Wheel$2,599$250 – $1,550
1995 KX80R5$2,599$225 – $1,185
1996 KX80R6$2,799$245 – $1,270
1997 KX80R7$2,819$225 – $1,060
1998 KX80W1$2,999$265 – $1,120
1999 KX80W2$2,999$270 – $1,145
2000 KX80W3$3,049$300 – $1,380

Street-Legal or Larger-Displacement Conversion?

As enduro-style bikes increasingly grow in popularity as city rides, more and more off-roaders eye on the KX80 as a good candidate for road-legal conversion. If one were to merely pay mind to requirements, converting a KX80 into a commuter that can ride on public roads seems pretty straightforward. After all, you only need to add the following:

  • DOT-compliant headlights
  • Switch-actuated high-and-low-beam lights
  • Brake light and taillight
  • 12V lighting coils, wiring, and battery
  • Rearview mirror
  • Turn signals
  • DOT-certified tires
  • License plate bracket with light
  • Electric horn

However, there is more to turning the KX80 into a street-legal than just completing requirements. You, the owner, will have to decide whether it is practical to convert the bike into a daily commuter or stick to improving its capabilities by upgrading its piston displacement and engine. Will it be worth the money spent to force an 82-cc dirt bike to perform like a trusty wheeler on pavement? Or would it make more sense to draw out its latent capabilities without disrupting its purpose through modifications?

Choosing the latter option would not be necessarily easier either. Optimizing the bike’s competencies entails not only an expensive build and equally expensive aftermarket parts but also a thorough understanding of which pieces go together to produce the best results. For instance, a stock airbox may be left as is by most riders. But a savvy owner would immediately see the airbox’s weird design and know to get a silencer that terminates ahead of the rear number plate – to keep the bike clean.

More Power

Similarly, an owner wanting more power would put a larger-than-stock sprocket on the rear wheel, a matching, larger chain, and a longer swingarm. This step will then warrant gearing changes, plus some suspension and top-end work. It would also be practical to have full digital instrumentation and EPA-friendly emission controls. Other noteworthy considerations are as follows:

  • Throttle responsiveness or improved rider input
  • High-speed stability
  • State-compliant wheelbase length
  • Lubrication system revamp (the KX80 having a pre-mix lubrication system may prove to be a pain in the long run, more so if intended as a daily driver)

Ultimately, it will be your preference and riding style that will determine the route you will take. Oh, and do not forget budget – you will find a lot of savants advising people to buy a 200-cc Chinese-made Enduro rather than spend money on a DS kit and repeated maintenance.

About Kawasaki

Kawasaki Heavy Industries, Ltd. is considered a force to be reckoned with in the world of motorcycling and powersports. While responsible for creating some of the most powerful and innovative machines in existence, the creator of Kawasaki KX 80 is also well-known for its off-road vehicles, side x sides, and watercraft.

Launching the KX80 in the market has been one of Kawasaki’s attempts to regain its foothold in the Enduro motorcycle scene. And although incomplete, the effort was a success. The Japanese firm was able to turn the KX80 lineup into a show of its strength – an industry prowess that continues to manifest in the company’s initiatives – aerospace and energy systems, transit, and hydraulic machinery – and other endeavors.

Dirt Bike Motorsport Motion

Conclusion – Kawasaki KX80 Review

The Kawasaki KX80 did not get upgraded from the factory in quantum leaps. But this does not necessarily mean the supplemental changes it received were for nothing. Like most wheelers in the ’80s, the KX80 – flaws, features, and all – was a necessary milestone for Kawasaki to get to where it is today. This minibike is proof that simple does the trick when it comes to adventure and fun. More importantly, it can turn into a virtual rocketship in the hands of a skilled rider.

Kris Peter

Adventure seeker and off-road enthusiast. I love the thrill of going off-road and taking on the elements.

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